Glucagon is a counter-regulatory hormone that is classically used to treat hypoglycemia. However, it can elicit the generation of cAMP within the myocardium to cause positive inotropic and chronotropic effects without the need for beta-1 adrenoceptor stimulation. Glucagon has been used extensively to treat beta-blocker overdose and has evidence for use in verapamil and imipramine overdose as well. Glucagon has been used as adjunctive therapy in shock situations and heart failure but is inferior to catecholamines. An interesting potential indication for glucagon is in treating postcountershock asystole.